A062649 Composite numbers with property that every divisor contains the digit 1.

121, 143, 169, 187, 221, 341, 361, 451, 671, 781, 961, 1037, 1111, 1133, 1159, 1177, 1199, 1207, 1243, 1271, 1313, 1331, 1339, 1349, 1391, 1397, 1417, 1441, 1469, 1507, 1529, 1573, 1639, 1651, 1661, 1681, 1703, 1717, 1727, 1751, 1781, 1793, 1807, 1819

Offset: 1

Author

Erich Friedman, Jul 04 2001

Keywords

• base
• easy
• nonn

Comments

Intersection of A002808 and A062634. - Michel Marcus, Sep 12 2013

Examples

			143 has divisors 1, 11, 13 and 143, all of which contain the digit 1.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A062634, A062653, A062664, A062667, A062669, A062670, A062671, A062672, A062673, A062674, A062675, A062676, A062677, A062678, A062679, A062680.

Programs

Mathematica

fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 1850], !PrimeQ[#] && fQ[#, 1] &] (* Robert G. Wilson v, Jun 11 2014 *)

PARI

lista(nn) = {forcomposite(n = 1, nn, ok = 1; fordiv(n, d, ok = ok && setsearch(Set(digits(d)), 1)); if (ok, print1(n, ", ")););} \\ Michel Marcus, Sep 12 2013